Weight seems to be the issue. I would be interested in seeing some posts with weight.
I have a Marlin Guide Gun but that is not apples to apples.
Here are the .327 Vs .32 H&R Magnum and .32-20 weights.
Our Henry .327 Federal weighs 7.05lb.
The Marlin 1894 in .32 H&R Magnum weighs 7.15lb.
The Marlin 1894CL in .32-20 weighs 6.50lb..

So the Henry is a half pound heavier than the Marlin .32-20.

Looking on the web sites Marlin lists Approximate weights.
20" 45-70 as approximately 7lb.
Henry says it 18.4" 45-70 weighs 7.08lb.

Marlin says a 20" .45 Colt weighs 6.5lb - approximately.
Henry says a 20" .45 Colt weighs 7.0lb.

Weight does not appear to be an issue.